With the rapid development of mobile terminal hardware technologies, more and more new functions with novelty and creativity are introduced in the field of mobile terminals, so as to enhance the availability and entertainment of mobile phones, and bring richer operation experiences and enjoyment to the users. The function of proximity sensing is one of the new functions. In order to realise the proximity sensing function, firstly, a proximity sensor, also referred to as a displacement sensor, needs to be implanted into the mobile terminal, which, in normal situations, is arranged at the two sides or in a groove of the mobile phone receiver. The principle thereof lies in calculating, through acquiring the physical variations of the monitored object, the distance from the sensor to the detected object.
At present, the hardware support for mobile terminals is upgraded gradually, and the multimedia experience of the user is also developing towards the direction of diversification; especially, file formats applicable for a video player have converted from the traditional lower-resolution formats such as .3gp, and .flv, to file formats which may play various types of files of high-definition or super-definition formats such as .avi and .mkv. The above-mentioned file types generally adopt the approach that the video file and caption file are separately processed, thus, when the video is played, if the mobile phone screen is placed too far, the caption or voice of the video will appear or sound relatively small; and if the mobile phone screen is placed too close, the caption or voice will appear or sound too big.
Therefore, in the traditional art, there is no such solution that the caption on the display screen of the mobile terminal or the voice from the mobile terminal may be adjusted adaptively with the change of the distance between the user and the display screen of the mobile terminal when the user watches the video on the mobile terminal.